Floor covering



Patented Mar. 23, 1937 PATENT OFFICE FLOOR COVERING Louis Leonard Larson and David Lindsay, In,

Wilmington, Del., assignors to Krafelt Corporation of America, Wilmington, DeL, a corporation of Delaware No Drawing. Application April 1, 1933, Serial.

4 Claims.

This invention relates to floor coverings, wall coverings, and the like, and more particularly to a process for making sheet material products of this nature by treating cellulose pulp with drying 5 oil and pigments.

This invention has as an object the production of improved floor coverings. A further object is an economic and advantageous method of manufacturing fioor coverings. Further objects will 10 appear hereinafter. 4

These objects, in the preferred embodiment of our invention, are accomplished by the formation of sheets of non-woven fabrics on paper making machines from fibrous cellulose pulps which have 15 been treated with drying oil paints.

In the manufacture of'fioor coverings by the process of'the present invention we treat fibrous.

( 1) A pulp, such as ordinary kraft pulp, is dis- 25 persed in water in a paper heater, or any other suitable dispersing apparatus, the ratio of water to pulp being such that the fiber content will not be less than about 3.5% and not more than substantially 5.5% by weight of themass of water and 30 pulp.' The pulp, after being beaten fora length of time sufiicient to disperse the fibers, is then dumped into a chest.

(2) To the pulp dispersion in the chest is added 35 a water emulsion of linseed oil paint which is thoroughly dispersed into the pulp. The preferred ratio of oil to fiber is from 0.4 to 1.66 parts by weight of oil for one part by weight of fiber. The minimum amount of oil is the smallest 40 amount required to carry the pigment onto the fiber and the maximum amount of oil is from about 2.5 parts by weight of oil for one part by weight of fiber. The preferred ratio of pigment to fiber is about 0.5 part by weight of pigment to 45 one part by weight of fiber. It is not desirable to use more than one part by weight of pigment to one part by weight of fiber or less than about 0.25 part by weight of pigment to one part by weight of fiber.

5 (3) A water solution of alum is added to the mixture consisting of the water dispersion of pulp and emulsified paint in an amount just sufilcient to precipitate the particles of the emulsified paint onto the fibers of the pulp.

55 (4) Water is added to reduce the fiber content of the paint treated pulp mixture to an amount not more than 0.5% by weight..

(5) The paint treated pulp, which should not contain more than about 0.5% by weight of fibers, is formed into a sheet by any of the regular meth- 5 ads well known to the paper industry. The formed sheet is then pressed to remove water and dried at 100 C.

(6) The dried sheet is aged for at least fortyeight hours at 65 C. to oxidize the drying oil. 10 The rate of drying is followed by determining the Mullen bursting strength.

Certain precautions should be observe'd'in prac ticing the invention by the process as described above. In the first place, the pulp in the chest from the beater should not contain less than 3.5% by weight of fibers in order to obtain good and uniiorm'precipitation of the particles of paint onto the fibers. The pulp during the precipita tion process is gently agitated. If rapidly agi-' tated the paint particles do not fix well onto the fibers. The pulp thus treated with paint has a tendency to form so-called bird's-eyes. These bird's-eyes", or knots of fibers, are removed by thorough agitation of the pulp after it has been diluted with water to paper making .consistency.

It is not recommended, however, to pass the paint treated pulp through a Jordan engine in order to remove the bird's-eyes because the bars of the engine tend to remove the paint from the surface of the fibers. Following sheet formation, the amount of pressure which may be applied to the sheet is dependent upon the amount of paint which has been precipitated onto the 'fibers. High pressure appliedto sheets formed from pulps treated with paint in excess, of the amount required to color the fibers causes paint to be ex-- pressed to the surface. On the other hand, considerable pressure can be applied to the wet sheet formed from fibers treated with just enough paint 40 to give good and uniform color.

For certain purposes it is advantageous to carry out our process by using either naturally ,or artificially crinkled fibers. The crinkled fibers, more specifically referred to hereinafter, prepared in accordance with Patent 1,857,100 issued to F. H. McCormick and G. L. Schwartz are particularly useful in the practice of the present invention. when these fibers are used, just enough of the emulsified paint is added in the second step to color the fibers. Because of the exceptionally high residual porosity of the base resulting from the 6th step, it is possible to print patterns on the sheet with dryin oil printing paint, the pattern or figure penetrating straight through the 5 sheet without appreciable spreading or filtering out of the pigment on the surface of the sheet. The printed sheet may then be impregnated with a transparent saturant, after which the sheet is 5 calendered to, increase its density. A final varnish or lacquer is then applied.

The properties of our products may be regulated by the choice of the fibers, the amount of paint precipitated on the fibers before sheet formation and by the use of fillers. When straight fibers are used, as for instance ordinary kraft pulp, with or without the addition of a filler such as wood flour, the final product resulting from the 6th step is a relatively non-absorbent, solid color, non-woven fabric which is strong and quite dense. When crinkled fibers are used, particularly the artificially crinkled pulp previously men- .tioned, the sheet resulting from the steps enumerated above is a porous, absorbent and very pliable solid color product which may be printed with printing inks or drying oil paints, filled with a transparent saturant, and finished by application of clear varnish or lacquer to the surface for the production of the decorative fioor coverings referred to above.

We may prepare our products in thicknesses ranging from 0.075" to 0.200". It is possible to I prepare even thicker sheets when the artificially crinkled fibers are used. As disclosed in the aforementioned patent, these fibers are made by treat ing paper pulp with caustic soda solution of mercerizing activity under conditions which do not permit the reaction between the pulp and caustic to proceed appreciably further than a mere superficial mercerizatior. or skin effect, the nonalpha cellulose constituents not being removed to any appreciable extent. This is accomplished by dispersing the pulp with the caustic at high pulp consistencies (a small ratio of liquor to fiber) and diluting and washing out the strong caustic from the pulp promptly after the mass of pulp and caustic have been passed through the mixing or dispersing apparatus. In making these artificially crinkled superficially mercerized fibers the caustic concentration should be of mercerizing strength, above 8% concentration at room temperature for most pulps. The preferred concentration is between 10.5 to 24%. This pulp has an extraordinarily high freeness which ranges from 15 seconds or less to 40 seconds as determined by the special freeness tester described in the mentioned patent. This pulp responds to the characteristic tests for mercerlz'ed fibers in that the fibers as viewed through 'the microscope have a wire or rod-like instead 01" a ribbon-like form, and if caustic soda is used.as the mercerizing agent the fibers give a blue stain with zinc chloriodine solution. For some purposes it is desirable to hydrate this artificially crinkled pulp, but without appreciable cutting or abrasion of the fibers, by long beating in water. This treatment,

disclosed in application Serial No. 616,323 filed June 9, 1932 by G. L. Schwartz, decreases the absorbency and freeness somewhat but increases the density and strength of the felted sheet. The

reference to artificially crinkled fibers in the claims means the artificially crinkled superficially EXAHPLE I This example illustrates the preparation of solid color non-woven fabrics from artificially The wet lap was dispersed in the water by a Hollander type beater. After beating just long enough to disperse the fibers, the pulp was dumped into a chest, where it was mixed with the paint emulsion. The pulp was well agitated during the addition of the paint emulsion. The solution of alum was then added, with gentle agitation of the paint treated pulp.

Formation of sheet 34,000 parts by weight of water was added to the above pulp. ".lhe diluted pulp was stirred well to disperse the fibers, and was then formed into a sheet. The wet sheet was placed between screens and pressed by passing through squeeze rolls. The pressed sheet was dried at 100 0., and was then aged for forty-eight hours at 65 C. The product was prepared in thicknesses ranging from 0.075" to 0.200". A product of 0.100" thickness weighs 1.5 pounds per 40" x 36" area. The artificially crinkled kraft fibers were prepared by mixing 1 part by weight of air dry kraft pulp with 4 parts by weight of a 22% solution of commercial grade sodium hydroxide. Mixing was continued for approximately 15 minutes. The fibers were then washed with water until free from sodium hydroxide. The washed fibers were pulped, and were then formed into wet lap on a wet lap paper machine. The method used for preparing the paint emulsion will be described hereinafter,

The product thus prepared is very porous, pliable and resistant to cracking when bent. The product is well colored, and the paint is uniformly distributed throughout the sheet. The porosity of the product permits its further impregnation. For example, decorative fioor covering may be prepared by printing designs or patterns into the product with printing inks or drying oil paints. A drying oil printing paint may have th following composition: I 1

4 Parts by weight Blown linseed oil 65 Pigments 35 French ochre 17.05 Red oxide 11.07 Tii'm'm! 4,93 Chrome yellow 0.89 Lampblack 1.06

10% turpentine solution of cobalt linoleate..- 1.6 Naphtha 33.0

saturant, such for example as oil, or a natural or synthetic resin blended with drying oil, or a cellulose ester lacquer. The viscosity of the solution of transparent saturant should be sufiiciently low to permit good penetration into the product. The product when dry may then be cured by aging at an elevated temperature, such as 65 C.

The printed, filled, and cured product may be further treated by calendering or pressing in a plate pressto increase the density of the sheet, and then applying a finishing coat of clearvarnish or lacquer. A suitable finishing lacquer may have the following composition:

Parts by a weight 5 second viscosity cellulose nitrate 10.6 Tricresyl phosphate 5.3 Ethyl acetate 35.8 Butyl acetate 12.5 Ethyl alcohol 35.8

EXAMPLE II A solid color fioor covering was prepared from a mixture of naturally straight and artificially crinkled fibers by substituting kraft fibers for of the artificially crinkled'kraft fibers under Example I. This partial substitution. of kraft fibers for the artificially crinkled fibers increase the density of the product.

EXAMPLE III This example illustrates the preparation of solid color floor covering from artificially crinkled fibers treated with a water emulsion of blown linseed oil paint before sheet formation. This product was prepared by substituting 716 grams of linseed oil paint emulsion "C" (described hereinafter) for the 238 grams of linseed oil paint emulsion A in the formula given under Example'I. I

Exmru: IV

This example illustrates the formation of a strong, dense, solid color floor covering from kraft fibers treated with light blue linseed oil paint before sheet formation;

The product was prepared as follows:

- The same procedure as given under Example I was followed.

Formation of sheet 34,000 parts by weight of water was added to the paint treated pulp and sheets formed by the method described under Example I. The sheets were dried at 100 C. and aged for 48 hours at 65 C.

The product thus prepared has a uniform color throughout the sheet, and it is strong and X818?- tively free from cracking when bent. Sheets of 0.100" thickness weighed 4.0 pounds per 40" x 36" area.

The water emulsions of linseed oil paints were prepared as follows:

Linseed oil paint emulsion A Parts by weight Mill base:

Blown linseed oil 42.2 Titanium dioxide 35.9 Prussian blue 6.3 Naphtha 15.6

Paint: 100.0 Mill base 100.00

10% turpentine solution of cobalt linoleate 0.85

100.85 Water emulsion:

Part I:

Paint 100.85 Sodium salt of petroleum sulfonic acids 4.2 Toluene 1.0 Part II:

0.7% water solution'of gelatin 31.8 Part III: 4

0.7% water solution of gelatin 63.6

The mill base was prepared by grinding the oil,

pigment, and solvent in a ball mill until the pig,- ments were well dispersed. Drier was then added to the mill base. In forming the emulsion, Part II was added dropwise to Part I, which was rapidly stirred. Part III was then added very rapidly. Stirring was stopped within 30 seconds after Part 111 had been added.

Linseed oil paint emulsion "B" An emulsion having the following percentage composition was prepared by the same procedure used for Emulsion A": 30.6% blown linseed oil, 8.65% titanium dioxide, 1.55% Prussian blue, 0.06% cobalt linoleate, 2.3% sodium salt of petroleum sulfonic acids, 0.55% turpentine, 8.75% naphtha, 0.32% gelatin, and 47.22% water.

Linseed oil paint emulsion. "C" An. emulsion having the following pe centage 15.5% pigments (15.3% French ochre. 1

lampblack, and 0.135% Para toner red), 0.04% cobalt linoleate, 1.45% sodium salt of petroleum sulfonic acids, 037% turpentine, 6.55% naphtha, 0.15% gelatin, and 47.14% water.

The artificially crinkled fibers used in Examples I and II were prepared as follows:

Wet lap kraft pulp (46% bone dry) 1960 pounds which had a i'reeness of 62 seconds, was shredded into small pieces and was then passed through a disc'refiner at a uniform rate where 3040 pounds of a 24.3% solution of sodium hydroxide at 24 C.

was added at a uniform rate. The strength of the solution in contact with the fibers was 18.0% and the consistency of fibers in the treated mass was 18.0%. "The. treated mass dropped continuously into a stream of water which conveyed it to a cylindrical continuous suction/washer where it was washed until all caustic solution was removed. This treated pulp had a freeness of 32 seconds.

In preparing the artificially crinkled pulp of Example III. a mixture of 1 part by weight of air dry kraft pulp and 4 parts by weight of a 22% solution of sodium hydrordde at 30 C. were fed composition was prepared by the same procedure. used for Emulsion "A": 28.8% blown linseed oil,

into a continuous kneader. The pulp was held in the kneader for 15 minutes, after which it was extended and washed with water until nearly I neutral. The last traces of alkali were neutralized 5 with su'lfurous acid. The washed pulp was then formed into wet lap on a wet lap machine. The artificially crinkled pulp had a freeness of 31 seconds.

Any fibrous cellulosic material known to the paper industry that is of sufiicient len th may be used for the practice of this invention. Fibers that may be used instead of kraft fibers are sulfite wood pulp, soda pulp, rope (Musa textiles) that has been dispersed into its ultimate fiber length. jute, pulp from cotton linters, pulp from cotton rags, and other cellulosic fibers used in thepaper industry. Fibers that can be artificially crinkled include kraft pulp, sulfite pulp, rope that has been dispersed into its ultimate fiber length, and other short fibers regularly used for paper making except the fibers from poplar and gum pulps which are too .short. The crinkled fibers are preferably made from pulps having a mean fiberlength of from 1.5 mm. to 4 mm. Animal fibers, such as wool, and asbestos fibers may be used in combination with vegetable fibers.

Although we prefer to use alum as the precipitant of the paint emulsion, other heavy metal salts such as CaCh or MgClz. or acids such as sulfuric acid, may be used as precipitants.

China-wood oil, Perilla'oil, soya bean oil, menhaden oil, corn oil, rape seed oil, and other drying or semi-drying oils are considered equivalents of linseed oil. Although we prefer drying or semi-drying oils, the invention may be practiced with non-drying ols, such as coconut oil. palm oil, castor oil, etc. Oils of the type mentioned in this paragraph are referred to as fatty oils in the claims.

Any of the well known methods for the preparation of emulsions may be used in preparing the water emulsions of drying oil paints. A procedure differentfrom. the one illustrated is to disperse the pigments in water, and then emulsi- 45 fy drying oil into, the water dispersion of pigments. A dispersing agent,- such as gelatin, is

used to promote dispersion of the pigments in water, and an emulsifying agent, such as sodium oleate, is used to emrulsify the drying oil in the 50 water dispersion of pigments. The reference to an aqueous emulsion of oil as used herein means adlspersion of minute drops of 'fatty oil in water. By the term aqueous emulsion of paint" we mean a dispersion of minute drops of paint 55 (consisting of fatty oil, pigment and solvent) in water.

Products of color other than light blue or brown may be prepared, although pigments which are iantagonistic to oil in water emulsions should be I 60 avoided. The color may be obtained with ormay contain fire retardants, such for example as gypsum, secondary ammonium phosphate, tricresyl phosphate, etc., for the purpose of fireprooiing the products.

70 Whileitisusuallydcsirabletousepaintsin the practice of our invention, the pigment mayv be omitted and emulsified drying oil may be used alone. Instead of treating the pulp with the paint emulsion prior to sheet formation we may 75 treat the wet sheet itself with the smuhion of bution throughout the sheet.

drying oil or of drying oil paint. Various methods may be used for impregnating the wet sheet with the emulsion. For example, the wet sheet may be passed through a bath of the water emulsion, or passed over rolls the bottom part of which run in a bath of the paint emulsion, or the emulsion maybe sprayed onto the sheet.

When the sheet has been prepared from the crinkled fibers, particularly the artificially crinkled fibers, the fioor covering may be made by impregnating the dried sheet with the emulsion of drying oil paint. When the base is made from straight fibers it is not possible to impregnate the dried sheet satisfactorily because of the considerable concentration of the paint on the surface which gives incomplete and uneven distri- Also, when the paint emulsion is applied on the wet end of the paper machine-the best results are obtained by forming the sheet from artificially crinkled fibers or a mixture of straight and artificially crinkled j fibers in order to obtain penetration of the emulsion into the sheet. We obtainmarkedly better results, however, by the method which consists in treating the pulp with the paint or oil emulsion before the pulp is felted into a sheet. The incorporation of the emulsified paint into the pulp and the precipitation of the paint onto the fibers makes possible a highly u orm dispersion of the paint in the sheet.

Our improved process of making fioor coverings, wall coverings, and similar fabric sheet material products is accompanied by important advantages from an economic standpoint as well as from the standpoint of obtaining a superior product.

The process for making the solid fioor covering, or the solid color, porous and absorbent base material for the preparation of decorative fioor covering as herein described has the advantage of a saving in time and equipment because the product is prepared by a single operation on regular paper making machines. An advantageous feature of the products of the present invention resides in their high strength and good flexibility which permits folding and bending the sheet without danger of cracking which is encountered in the handling of linoleum or bitumen impregnated felt base fioor coverings. When the fioor coverings are prepared from the artificially crinkled fibers, or from pulp containing a fair proportion of these fibers, the products can be printed with printing inks or drying oil paints in designs or patterns which extend practically through the sheet. Consequently, the decorative effect lasts until the sheet is worn through from top to bottom. The product also resists wear after'it is partially worn as well as when it is new because ofthe uniformity in composition throughout the sheet.

As many apparently widely diiferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereofexcept defined in the following claims.

We claim:

1. A process which comprises adding an aqueous emulsion of fatty oil paint to an aqueous dispersion of, paper pulp, said pulp comprising artificially crinkled superficially mcrcerised fibers, intimately mixing the emulsion with the pulp, precipitating the particles of emulsified paint onto the fibers of the pulp, making thelnixture of precipitated paint and pulp into sheets. drying the sheets, printing a pattern substantially through the sheets with printing paint, and curing the printed sheets.

2. The process set forth in claim 1 in which the paint is present in an amount which furnishes not less than 0.25 part by weight of pigment for each part by weight of pulp.

3. A process which comprises adding an aqueous emulsion of fatty oil paint to an aqueous dispersion of paper pulp, said pulp comprising artificially crinkled superficially mercerized fibers, intimately mixing the emulsion with the pulp, precipitating the particles of emulsified paint onto the fibers of the pulp, making the mixture of precipitated paint and pulp into sheets, drying the sheets, printing a pattern into the sheets, curing the printed sheets, filling the residual voids by impregnation with a saturant, curing the saturated sheets, compressing the sheets 2 under pressure, and applying a finishing, composition to the surface of the sheets.

4. A process which comprises adding to an aqueous dispersion of paper pulp an aqueous emulsion of paint, intimately mixing the emulsion with the'pulp, said pulp comprising in sub stantial amount artificially crinkled superficially mercerized fibers, precipitating the particles of emulsified paint onto the fibers of the pulp, making the mixture of pulp and precipitated paint into sheets, and drying the sheets, the fiber content of said pulp dispersion being from 3.5% to 5.5% by weight of the mass of water and pulp,

T LOUIS LEONARD LARSON.

DAVID LmDsAY, .m. 

